Physics - February 2007

2007-02-08 13:34:41 · 2 answers · asked by >() 1

1)While lowering a 25 kg crate off the back of a 1m truck, a man exerts a force of 215N on the crate. How fast was the crate moving as it hit the ground?

2) A 55.2 kg box is pushed at a constant velocity up a frictionless ramp that is 10m long and 7m high. How much work will be done on the box in moving it to the top of the incline?
How much work will be done if the coefficient of friction is 0.18 between box and surface of the ramp?

8) An 18.8 kg object is accelerated from rest through a distance of 7.8m in 2.9s across a level floor. If the force due to friction between the object and the floor is 18.5N, what is the work done in moving the object?

9) A 12 255 kg truck traveling at 22.3 km/h is brought to a stop skidding 18m. Calculate work done by the truck by its brakes.
Calculate the work done by the trucks brakes if its initial speed was twice the vale stated above.




THANK YOU VERY MUCH!!

2007-02-08 13:28:16 · 1 answers · asked by ? 2

its apart of physical science

2007-02-08 13:22:40 · 4 answers · asked by missy 2

An exceptional standing jump would raise a person 0.80m off the ground. To do this, what force must a 66-kg person exert against the ground? Assume the person crouches at a distance of 0.20m prior to jumping, and thus the upward force has this distance to act over before he leaves the ground.

2007-02-08 13:16:24 · 1 answers · asked by champers 5

a- accelerating down a hill b- going faster and faster c- slowing down d- maintaining a constant velocity Please need help

2007-02-08 13:06:13 · 11 answers · asked by Justin D 1

what is the mass of the ball?

2007-02-08 12:53:00 · 3 answers · asked by Taylor 1

2007-02-08 12:47:08 · 6 answers · asked by Buck BUCK 2

I don't believe that it is possible to do, but a buddy of mine thought it was. Can you jump and grab onto the helicopter as it is hovering? The question arose while watching Goldeneye. Towards the end, James Bond jumps onto the helicopter from the satellite dish.

2007-02-08 12:41:33 · 4 answers · asked by Drew W 1

A car accelerates uniformly from rest to a speed of 40.0 mi/h in 12.0s. Find a) the distance the car travels during this time and b) the constant acceleration of the car. I'm trying to study for a test and I cannot figure out this answer. Other students from my class cannot figure it out as well. Any help would be great! Thank you so much!

2007-02-08 12:13:58 · 8 answers · asked by Anonymous

the velocity before it hit the ground. dont u use the change X = initial velocity * time +1/2at^2 to find the time it took. But what equation do u plug it into to find the velocity before it hits the ground????? Cuz in the problem, there tossin a rock up at a speed, dropping in it from rest, and throwing it down with a velocity.

2007-02-08 12:11:42 · 3 answers · asked by Greg 1

in the time dilation formula, is c the speed of light in vaccuum or the speed of light in whatever medium through which the observed oject is moving? why?

2007-02-08 12:09:52 · 4 answers · asked by Anonymous

2007-02-08 12:07:58 · 13 answers · asked by Tony 1

a.1/6
b.6
c.3
d.1/3

2007-02-08 12:03:54 · 3 answers · asked by elona 1

How can an object thats moving at a constant velocity be in equilibrium if in order for it to be in equilibrium the net force has to be 0?

I think it has something to do with equal and opposite and equilibrant but im not sure and it's confusing...

2007-02-08 11:58:50 · 7 answers · asked by Liz 3

2007-02-08 11:54:20 · 6 answers · asked by dulce m 1

This category has more "can somebody do my homework for me" questions than other categories, except maybe math. Are high school teachers not doing there jobs?

2007-02-08 11:47:40 · 11 answers · asked by Answer guy 2

2007-02-08 11:45:22 · 3 answers · asked by leyna_nguyen_0702 2

A train traveling at 100 kmph overtakes a motorbike traveling at 64 kmph in 40 seconds. What is the length of the train in meters?
The answer is 400 METERS. can someone kindly explain how to arrive at that answer?

2007-02-08 11:40:42 · 4 answers · asked by Anonymous

scientific notation?
that darn physics again, I have a quiz tommorow

2007-02-08 11:33:33 · 4 answers · asked by makelovenothate 2

so what are they? The tension energy is a factor, but what else?
Thanks.

2007-02-08 11:30:27 · 8 answers · asked by Anonymous

???

2007-02-08 11:29:06 · 6 answers · asked by Anonymous

Date will be collected from a cart travelling down a ramp with a ticker tape timer. The dots that are recorded will not be evenly spaced.
Once your ticker tape hass been made,choose a starting point on the tape where the dots are easly distinguished.Mrark this point t=0,0
The timer makes dots at intervals of 0.1s.mark off the time intervals from 0.0s to 1.0s and record the interval time in the observation table.This is a constant value.
Measure each interval distance using a ruler and record these values in the table.
Calculate the average speed for each interval and record these values in the table.
Measure the total distance traveled from your starting point(postion)after each time interval and record these values.
Any idea how i do this, i do't get it

2007-02-08 11:27:45 · 1 answers · asked by Anonymous

HRW5 10-3E The National Transportation Safety Board is testing the crashworthiness of a new car. The 1.36 103 kg vehicle, moving at 15.6 m/s, is allowed to collide with a bridge abutment, being brought to rest in a time of 0.465 s. What force, assumed constant, acted on the car during impact?
N

2007-02-08 11:27:40 · 4 answers · asked by ckielblock18 1

thanks, physics is my ultimate nigthmare

2007-02-08 11:21:19 · 18 answers · asked by makelovenothate 2

We know that metal expands when heated, so what will happen if you cut a hole the size of a quarter in the center of a cookie sheet, then pop it in the oven until it's very hot? Will a quarter still fit in the hole? Will the hole be bigger or small and why?

Thanks!

2007-02-08 11:18:54 · 2 answers · asked by Wael K 2

to measure their instantaneous power output.

A recreational cyclist riding on a horizontal surface averaged 420 watts and 23 miles per hour for 1 hour of riding.
Assuming the body is 40% efficient (i.e. it consumes 60% of total work to output the 40%)
How many food calories did the cyclist burn?

If one cup of cooked rice is 225 calories, how many bowls of rice would the cyclist eat to replenish the energy consumed?

What is the average resistance the cyclist overcame to achieve this?

2007-02-08 11:00:49 · 2 answers · asked by odu83 7

im in 9th grade and for some reason my indirect measurements arent working out..

2007-02-08 10:49:14 · 6 answers · asked by pointytissuexl3 3

2007-02-08 10:37:36 · 2 answers · asked by david w 5

2007-02-08 10:34:40 · 5 answers · asked by kenan33342 2

a proton
b. neutron
c electron
d positron

2007-02-08 10:32:24 · 8 answers · asked by Anonymous