As long as it sits on the shelf, its potential energy
relative to the floor is . . .

 Potential energy = (mass) x (gravity) x (height) =

 (3 kg) x (9.8 m/s²) x (0.8m) = 23.52 joules .

If it falls from the shelf and lands on the floor, then it has exactly that
same amount of energy when it hits the floor, only now the 23.52 joules
has changed to kinetic energy.

 Kinetic energy = (1/2) x (mass) x (speed)²

 23.52 joules = (1/2) x (3 kg) x (speed)²

Divide each side by 1.5 kg : 23.52 m²/s² = speed²

Take the square root of each side: speed = √(23.52 m²/s²) = 4.85 m/s  (rounded)

6 0

3 years ago

Helpp me outtttttttt

grandymaker [24]

Answer:

hope this helps you

Explanation:

bye bye

4 0

2 years ago

A car starting from rest has a constant acceleration of 4 meters per second per second. How fast will it be going in 5 seconds?

irinina [24]

Answer:

18 m

Explanation:

Given : vo = 0 m/s ; t = 3 s; a = 4 m/s^2 ; d = ? m ; average velocity = ? m/s ; fonal velocity = ? m/s

solving for the final velocity, v

v = a * t

v = 4 m/s^2 * 3 s

v = 12 m / s

Solving for the average velocity. avg v

avg v = (vo + v) / 2

avg v = (0 m / s + 12 m/s) / 2

avg v = 6 m / s

Solving for the distance traveled after 3 s

d = avg v * t

d = 6 m / s * 3 s

d = 18 meters

In the first 3s the car travels 18 meters.

4 0

2 years ago

The velocity time graph of a car shown below a) Calculate the magnitude of displacement of the car in 40 seconds. b) During whic

Gekata [30.6K]

Answer:

a) 0 metres

b) From time 0 s to 10 s , the car was accelerated. Its velocity accelerated from 0m/s to 20 m/s

c) 20 m/s

Explanation:

a) Formula of displacement= velocity x time

time=40 s

velocity =0 m/s

∴ displacement= 0 x 40 = 0 m

Magnitude of displacement is 0 m

b) The increase in velocity shows that there has been acceleration.

c) The average velocity of the car is = $\frac{0+40}{2\\}$ {initial velocity + final velocity}

= $\frac{40}{2}$

=20

Therefore, the magnitude of the average velocity of the car is 20 m/s

3 0

2 years ago