Answer:

Explanation:
Given that,
Mass of a boy is 78 kg
Mass of a girl is 65 kg
We need to find the force of gravitational attraction between them if they are 2 m away.
The formula for the gravitational force is given by :

So, the force between them is
.
Answer:
v = 5.75 x 10⁶ m/s
Explanation:
The radius (r) of the circular orbit taken by a charged particle is related to its speed perpendicular to a magnetic field of strength B, and is given by
r =
--------------(i)
Where,
q = charge of the particle
m = mass of the particle
Making v subject of the formula in equation (i) above gives
v =
-------------------(ii)
Given;
r = 20cm = 0.2m
B = 0.3T
v = unknown
q = charge of proton = 1.6 x 10⁻¹⁹ C
m = mass of the proton = 1.67 x 10⁻²⁷kg
Substitute the values of m, q, B and r into equation (ii) above to get;
v = 
Solving for v gives:
v = 5.75 x 10⁶ m/s
Therefore, the velocity of the proton is 5.75 x 10⁶ m/s
The answer is:
Heat from the ankle is transferred to the ice pack.
The explanation:
-when the ice pack a lower temp than the ankle , it is very cool.
- and the injured ankle has a high temp or heat
and we know that Q transfer from the object with high heat to the object with the low temp So,
Heat will transfer from the ankle to the ice pack.
When placing each domino upright, potential energy is conserved in that domino. When kinetic energy is initially added into the first domino, this energy converts the next domino's potential energy to kinetic energy, which is transferred to the next domino afterwards.
Answer:
B) The train is not an inertial frame of reference
C) The train may be instantaneously at rest
D) The train may be moving at a constant speed in a circle
H) The train must be accelerating.
Explanation:
Since the train is in constant motion, it is accelerating. The speed is varying with time. The train is not an inertial frame of reference since it is constantly moving.