Answer:
Explanation:
a). Find the graph attached for the motion.
b). If a shopper walk 5.4 m westwards then 7.8 m eastwards,
Distance traveled by the shopper = Distance traveled in eastwards + Distance traveled westwards
= 5.4 + 7.8
= 13.2 m
c). Displacement of the shopper = Distance walked westwards - Distance traveled eastwards
= 5.4 - 7.8
= -2.4 m
Therefore, magnitude of the displacement of the shopper is = 2.4 m
And the direction of the displacement is eastwards.
Answer:
12500W
Explanation:
Given parameters:
Work done = 250000J
Time taken = 20s
Unknown:
Power of the crane = ?
Solution:
Power is the defined as the rate at which work is being done;
Mathematically;
Power = 
insert the parameters and solve;
Power = 
= 12500W
A girl standing on a floor would have two opposite forces acting on it. These forces are the weight and the normal force. Since no other forces are acting and that the girl is at rest, then the weight must equate to the normal force. Therefore, the supporting force would be:
F = mg = 55kg (9.81 m/s^2) = 539.55 N
Answer:
V = I×R
where -
V = potential difference across
I = current flowing in the circuit
R = Equivalent Resistance in the circuit
Let's call the constant acceleration a.
At a time t, its speed will thus be v(t)=a*t+v0 where v0 is its initial speed, here 10 m/s. Hence v(t)=a*t+10.
From there we can deduce the position P(t)=a*t^2/2+10t+p0 where p0 is the initial position, here 0.
Hence P(t)=a*t^2/2+10t
Let's call T the time at which it's at 50 m/s, we know that P(T)=225m and that v(T)=50 m/s hence a*T+10=50 thus a=40/T and P(T)=(40/2+10)T=30T
Hence T=225/30=7.5
It took 7.5 seconds
