Answer:
The average recoil force on the gun during that 0.40 s burst is 45 N.
Explanation:
Mass of each bullet, m = 7.5 g = 0.0075 kg
Speed of the bullet, v = 300 m/s
Time, t = 0.4 s
The change in momentum of an object is equal to impulse delivered. So,

For 8 shot burst, average recoil force on the gun is :

So, the average recoil force on the gun during that 0.40 s burst is 45 N.
Answer : B) The cow pulls back on the girl.
From newton’s third law we know that every action has a reaction force pushing back. So when the girl pulls on a cow, the cow is pulling back on her.
Answer:
e. 1.2 x 10²³
Explanation:
According to the problem, The current equation is given by:

Here time is in seconds.
Consider at t=0 s the current starts to flow due to battery and the current stops when the time t tends to infinite.
The relation between current and number of charge carriers is:

Here the limits of integration is from 0 to infinite. So,


q = 1.90 x 10⁴ C
Consider N be the total number of charge carriers. So,
q = N e
Here e is electronic charge and its value is 1.69 x 10⁻¹⁹ C.
N = q/e
Substitute the suitable values in the above equation.

N = 1.2 x 10²³
Answer:
100 Watts
Explanation:
<u>These equations are needed to work out the answer:</u>
- power= work done/ time taken
- work done= force* distance
- force= mass* acceleration
force: 10 kg* 2m/s= 20
work done: 20* 10m=200
power: 200/2=100