Answer:
the speed of the ball is 10 m/s
Explanation:
Given;
magnitude of exerted force, F = 400 N
mass of the ball, m = 2 kg
radius of the circle, r = 0.5
The speed of the ball is calculated by applying centripetal force formula;

Therefore, the speed of the ball is 10 m/s
 
        
                    
             
        
        
        
Pretty sure physical, a chemical change would be something of the time of acid rain, meanwhile physical changes are the ones that affect the form not the actual chemical composition
        
             
        
        
        
People are asleep at 3 am so energy would be less then.
        
                    
             
        
        
        
Answer:
<em>The velocity of the two cars is 10 m/s after the collision.</em>
Explanation:
<u>Law Of Conservation Of Linear Momentum
</u>
The total momentum of a system of bodies is conserved unless an external force is applied to it. The formula for the momentum of a body with mass m and velocity v is 
P=m.v
If we have a system of bodies, then the total momentum is the sum of them all

If some collision occurs, the velocities change to v' and the final momentum is:

In a system of two masses, the law of conservation of linear momentum  takes the form:

If both masses stick together after the collision at a common speed v', then:

The car of mass m1=1000 Kg travels at v1=25 m/s and collides with another car of m2=1500 Kg which is at rest (v2=0).
Knowing both cars stick and move together after the collision, their velocity is found solving for v':



v' = 10 m/s
The velocity of the two cars is 10 m/s after the collision.
 
        
             
        
        
        
The μs between the clock and floor is 650(M*g) and the μk between the clock and the floor is 560(M*g)