Physics Questions and Answers
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
A car of mass 800kg attains a speed of 25m/s in 20secs. The power developed in the engine is?
1.25 x 10\(^{4}\)W
2.50x 10\(^{4}\)W
1.25 x 10\(^{6}\)W
2.50 x 10\(^{6}\)W
Correct answer is B
P = \(\frac{mv^{2}}{t} = \frac{800 \times 25 \times 25}{20}\)
2.5 x 10\(^{4}\)W
5J
10J
15J
20J
Correct answer is C
m = 0.1kg
u = 10ms\(^{-1}\)
h = 10m
g = 10ms\(^{-2}\)
At h\(_{max}\); v = 0
Using
\(\not v\) = \(\not u\) = \(\not gt\)
\(\not 0\) = \(\not w\) - \(\not 10t\)
v\(^{2}\) = u\(^{2}\) - 2gh
0\(^{2}\) = 10\(^{2}\) - 2 x 10h
20h = 100
h = 5m
Total height = 10 + 5
= 15m
Total energy = mghr = 0.1 x 10 x1 5
= 15J
50J
100J
150J
200J
Correct answer is A
Given
m\(_{1}\) = 0.05kg, u\(_{1}\) = 200ms\(^{-1}\), m\(_{2}\) = 0.95kg
K.E = \(\frac{1}{2}\)m\(_{r}\)v\(^{2}\)
m\(_{1}\)u\(_{1}\) = v(m\(_{1}\) + m\(_{2}\)) [law of conversation of momentum]
v = \(\frac{0.05 \times 200}{0.05 + 95}\) = 10ms\(^{-1}\)
K.E = \(\frac{1}{2}\)(1)10\(^{2}\) = 50J
2N
20N
200N
400N
Correct answer is B
Given
m = 10\(^{-2}\)
w = 100rads\(^{-1}\)
F = mw\(^{2}\)r
r = 0.2m
F = ?
= 10\(^{-2}\) x (100)\(^{2}\) x 0.2
= 20N
1:4
2:1
2:3
2:5
Correct answer is C
Given \(\frac{m_{1}}{m_{2}} = \frac{3}{1}\) \(\Rightarrow\) m\(_{1}\) = 3m\(_{2}\)
\(\frac{a_{1}}{a_{2}} = \frac{2}{9}\) = a\(_{1}\) = \(\frac{2a_{2}}{9}\)
\(\frac{F_{1}}{F_{2}}\) = ?
Since F = ma
\(\Rightarrow\) \(\frac{F_{1}}{F_{2}} = \frac{m_{1}a_{1}}{m_{2}a_{2}}\) = \(\frac{(3 \not m_{2})(2 \not a_{2})}{\not m_{2} a_{2} \not a_{3}}\)
\(\frac{F_{1}}{F_{2}} = \frac{2}{3}\) \(\Rightarrow\) 2:3