Homework Answers

A cargo was dropped down a helicopter which hovered at height of h=125m

When will the cargo reach the land?free fall acceleration is g=10m/s2.Air resistance must be ignored

a toaster, operating on a household circuit (v=120 v) shows 10A of current on an ammeter. what is the power rating of the toaster?

truck travelling at 22.5 m/s decelerates at 2.27 m/s2

. (a) How much time does it take for the truck to stop? [9.91 ]s

(b) How far does it travel while stopping? [112m]

(c) How far does it travel during the third second after the brakes are applied? [

A trophy sits on top of a shelf 2.30 m above the floor. If the trophy has a potential energy of 90 J, its mass is __________ kg.

A trolley rolls down a slope at a constant acceleration.

It travels 8.0 m in 4.0 s.

(a) Plot the velocity-time graph for the motion of the

trolley

(b) Find the acceleration of the trolley

A car drove away from its stationary position with a constant acceleration of 5.0 m s-2. 

Plot its motion in the velocity-time graph below for the first 5.0 seconds of travel.

(a)   How long does it take the car to reach a speed of

20.0 ms-l?

(b)  How far did the car travel during this time?

A car starts from rest and accelerates at a constant rate, reaching a speed of 5.0 m s-^ in 10.0 s. 

It then travels at this speed for 30.0 s before coming to a stop in another 5.0 s.

(a) Plot the velocity-time graph of the car.

(b) Find the total displacement of the car.

A football was moving at a speed of 1.2 ms-1 when it was kicked towards the opposite direction.  The impact time was 0.2 s and the final speed was 5.0 m s-1.  Find the average acceleration of the ball during the impact.

A disk of radius 1.20cm. It has a charged of -6.0nC spread uniformly over the said disk. Find the magnitude and direction of the electric field this disk produces at point A on the axis of the disk a distance of 2.0cm from its center