Answer:
4 times the mass of Earth
Explanation:
= Mass of Earth
= Mass of the other planet
r = Radius of Earth
2r = Radius of the other planet
m = Mass of object
The force of gravity on an object on Earth is

The force of gravity on an object on the other planet is

As the forces are equal

So, the other planet would have 4 times the mass of Earth
Answer:4.39 s
Explanation:
Given
initial velocity 
acceleration 
velocity acquired by sled in
time


distance traveled by sled in 



distance traveled in
time with velocity 




----1


substitute the value of
in 1
we get

thus 

Answer:
The magnetic field strength of an electromagnet is therefore determined by the ampere turns of the coil with the more turns of wire in the coil the greater will be the strength of the magnetic field.
Explanation:
Answer:
a) Impulse(J)=40.04 kg.m/s
b)F=2566.66 N
Explanation:
Given that

We know that impulse(J) impulse is a vector quantity

We know that P=mV
So
Now by putting the values
J=1.3(9.8-(-21))
So impulse(J)=40.04 kg.m/s
Force is given as

or we can say that

So 
F=2566.66 N