We can use the equation of motion:
s = ut + 1/2 x at²
Both the velocity and acceleration are downwards so we'll consider the downward direction positive
30 = 8t + 4.91t²
4.91t² + 8t - 30 = 0
Solving the quadratic:
t = 1.79 s; t = -3.42 s
Negative time is not possible so second value discarded. Time taken = 1.79 seconds
Hi there!
If they are in opposite direction:
- Let UP be the POSITIVE direction and DOWN be the NEGATIVE direction.
Thus:
∑F = 114.6 - 70.7 = 43.9 N upward
If they are in the SAME, downward direction:
∑F = -114.6 - 70.7 = -185.3
The magnitude is the absolute value, so:
|-185.3| = 185.3 N downward
Answer:
energy of motion decrease
Explanation:
yes
Answer:
(a) vf = 1.51 m/s
(b) vf = 36.22 m/s
Explanation:
The rate of change of momentum is equal to the force:
where,
F = Force = 1035 N
t = time = 0.175 s
vi = initial speed = 0 m /s
vf = final speed = ?
(a)
m = mass of body = 120 kg
Therefore,
<u>vf = 1.51 m/s</u>
<u></u>
(b)
m = mass of head = 5 kg
Therefore,
<u>vf = 36.22 m/s</u>
Firstly SI units must be used so 1 mile = 1069,344 metres. Thus 1.5 miles = 2414,016 m
Now SI unit for time is seconds so 0.5 hours = 1800 seconds
Now speed is equal to distance over time thus 2414,016 ÷ 1800 = 1,34
The unit for this is metres per second = m.s^-1
Now speed is a scalar quantity which has no direction but has magnitude thus the speed is 1,34 m.s^-1
And velocity is a vector quantity thus it has both magnitude and direction thus the velocity us 1,34 m.s^-1, south
Note that speed is equal to velocity the only difference is that one must have direction and one must not have direction, due to the scalar and vector property l.