Answer:
mass of the ball will be 1 kg
Explanation:
We have given force F = 0.5 N
This force must be equal to the centripetal force for the ball to revolve in the circle
So 
Centripetal acceleration is given as 
We have to calculate the mass of the ball
We know that force is given by

So 
m = 1 kg
So mass of the ball will be 1 kg
The minimum velocity of the Salmon jumping at the given angle is 12.3 m/s.
The given parameters;
- height of the waterfall, h = 0.432 m
- distance of the Salmon from the waterfall, s = 3.17 m
- angle of projection of the Salmon, = 30.8º
The time of motion to fall from 0.432 m is calculated as;

The minimum velocity of the Salmon jumping at the given angle is calculated as;

Thus, the minimum velocity of the Salmon jumping at the given angle is 12.3 m/s.
Learn more here: brainly.com/question/20064545
Answer:
Q= -6900 J
Explanation:
use the formula Q=mC(T_2 - T_1) and sub in givens
Q=mC(T_2 - T_1)
Q= (200 g)(0.444 J/g°C)(22-100)
Q= -6900 J
The negative sign means heat is lost, which agrees with the decrease in temperature
2.71 m/s fast Hans is moving after the collision.
<u>Explanation</u>:
Given that,
Mass of Jeremy is 120 kg (
)
Speed of Jeremy is 3 m/s (
)
Speed of Jeremy after collision is (
) -2.5 m/s
Mass of Hans is 140 kg (
)
Speed of Hans is -2 m/s (
)
Speed of Hans after collision is (
)
Linear momentum is defined as “mass time’s speed of the vehicle”. Linear momentum before the collision of Jeremy and Hans is
= 
Substitute the given values,
= 120 × 3 + 140 × (-2)
= 360 + (-280)
= 80 kg m/s
Linear momentum after the collision of Jeremy and Hans is
= 
= 120 × (-2.5) + 140 × 
= -300 + 140 × 
We know that conservation of liner momentum,
Linear momentum before the collision = Linear momentum after the collision
80 = -300 + 140 × 
80 + 300 = 140 × 
380 = 140 × 
380/140= 
= 2.71 m/s
2.71 m/s fast Hans is moving after the collision.