Answer:
it's false coz
Speed is a scalar quantity.
Answer:
25032.47 W
Explanation:
Power is the time rate of doing work, hence,
P = Work done(non conservative) / time
Work done (non conservative) is given as:
W = total K. E. + total P. E.
Total K. E. = 0.5mv²- 0.5mu²
Where v (final velocity) = 7.0m/s, u (initial velocity) = 0m/s
Total P. E. = mgh(f) - mgh(i)
Where h(f) (final height) = 7.2m, h(i) (initial height) = 0 m
=> W = 0.5mv² - mgh(f)
P = [0.5mv² - mgh(f)] / t
P = [(0.5*790*7²) - (790*9.8*7.2)] / 3
P = (19355 + 55742.4) / 3 = 75097.4/3
P = 25032.47 W
Answer:
K.E = 100 J
Final P.E = 100 J
Explanation:
The kinetic energy of any object can be given by the following formula:
where,
K.E = Kinetic Energy
m = mass of ball = 2 kg
v = speed of ball
Initially, v = 10 m/s. Therefore, the initial K.E is given as:
<u>K.E = 100 J</u>
Now, at the highest point the K.E of the ball becomes zero. because the ball stops for a moment at the highest point and its velocity becomes zero. So, from Law of Conservation of energy:
Initial K.E + Initial P.E = Final K.E + Final P.E
Initial P.E is also zero due to zero height initially.
K.E + 0 = 0 + Final P.E
<u>Final P.E = 100 J</u>
Answer:
t = 8 s
Explanation:
In order to find the time taken by the dragster we will use equations of motion. Here, we will use second equation of motion:
s = Vi t + (1/2)at²
where,
s = distance covered = 320 m
Vi = Initial Velocity = 0 m/s (Since, dragster starts from rest)
t = time taken = ?
a = acceleration of dragster = 10 m/s²
Therefore,
320 m = (0 m/s)t + (1/2)(10 m/s²)t²
t² = (320 m)(2)/(10 m/s²)
t = √(64 s²)
<u>t = 8 s</u>
Answer:
Scientific models are representations of objects, systems or events and are used as tools for understanding the natural world. Models use familiar objects to represent unfamiliar things. Models can help scientists communicate their ideas, understand processes, and make predictions.
