Answer:
A. 16.67 m/s
Explanation:
Speed or velocity refers to the rate of change in distance over a change in time. That is;
Speed = Distance ÷ time
Where;
Speed is in metre/seconds
Distance is in metre
Time is in seconds.
In this question, Steve throws a football 50 meters in 3 seconds. The average speed can be calculated this:
S = D/t
Where; d = 50m, t = 3s
S = 50/3
S = 16.6666666
S = 16.67m/s
Answer:
Because it has more mass
Explanation:
To understand this, think about the equation of kinetic energy
KE =
m 
Kinetic energy depends on both the velocity (v) as well as the mass (m).
Because a lorry is bigger and heavier than a car, it will have more mass. With more mass, at the same velocity the lorry with have more kinetic energy.
KE = 1/2 * m * v2
We have to rearrange this so the subject is mass. (because the question asks for the mass of the object) :
Mass = (2 * KE) / v
Now input the values into this equation to get your answer :
Mass = (2 * KE) / v
Mass = (2 * 480) / 8
Mass = 960 / 8
Mass = 120