Answer: 90 meters
Explanation: 60/20=3 and 3*30=90 so it is 90 meters.
 
        
                    
             
        
        
        
Answer:
-24 m/s
Explanation:
mass of the bowling ball =  3 kg
time (t) = 0.3 seconds
Force = 24 N
initial velocity u = ???
We know that;
Force = mass × acceleration (a)
So;
24 = 3 × a
a = 24/3
a = 8 m/s²
Also; 
From equation of motion; acceleration is given by the relation;

if v = 0 
then ;

24 = 0- u
u = -24 m/s
Thus; the  initial velocity of the bowling ball when it first touched the mattress =  -24 m/s
 
        
             
        
        
        
Explanation:
We have,
Length of a metal rod is 55 cm or 0.55 m
Change in length is 0.2 cm or 0.002 m
It is required to find the change in temperature of a metal rod. The coefficient of linear expansion is given by :

 is the change in temperature
 is the change in temperature

So, the change in temperature is 303.03 degrees Celsius.
 
        
             
        
        
        
Answer:
18.6 m/s
Explanation:
 = Initial height of the balloon = 11 m
 = Initial height of the balloon = 11 m
 = initial speed of the ball
 = initial speed of the ball 
 = initial vertical speed of the ball = 7 m/s
 = initial vertical speed of the ball = 7 m/s
 = initial horizontal speed of the ball = 9 m/s
 = initial horizontal speed of the ball = 9 m/s
initial speed of the ball is given as 

 = final speed of the ball as it strikes the ground
 = final speed of the ball as it strikes the ground
 = mass of the ball
 = mass of the ball
Using conservation of energy 
Final kinetic energy before striking the ground = Initial potential energy + Initial kinetic energy

 
        
                    
             
        
        
        
Answer:
Distance, Brighter
Explanation:
Think of a flash light, one close and one far which is brighter and which is dimmer.   
 Hope this is what your teacher put as the answer!