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Q47.
Step 1: Identify the given values and relevant formulas.
Mass of car, m=1200 kg
Power, P=54kW=54000 W
Angle of inclination, θ=sin−1(101), so sinθ=101
Non-gravitational resistance, R=300 N
Acceleration due to gravity, g=10ms−2
At maximum speed, the net force is zero, and power is given by P=Fv, where F is the total force opposing motion.
Step 2: Calculate the component of gravitational force acting down the incline.
Fg=mgsinθ
Fg=(1200kg)(10ms−2)(101)
Fg=1200N
Step 3: Calculate the total opposing force.
The total opposing force is the sum of the gravitational component and the non-gravitational resistance.
Ftotal=Fg+R
Ftotal=1200N+300N
Ftotal=1500N
Step 4: Calculate the maximum speed v.
Using the power formula P=Ftotalv:
v=FtotalP
v=1500N54000W
v=36ms−1
The options provided are A. 20ms−1, B. 25ms−1, C. 100ms−1, D. 900ms−1.
There seems to be a discrepancy between the calculated answer and the given options. Let me recheck the calculation.
P=54kW=54000 W.
m=1200 kg.
sinθ=1/10.
R=300 N.
g=10ms−2.
Force due to gravity down the incline: Fg=mgsinθ=1200×10×(1/10)=1200 N.
Total resistive force: Ftotal=Fg+R=1200N+300N=1500 N.
Maximum speed: v=P/Ftotal=54000W/1500N=36ms−1.
Given the options, none of them match 36ms−1. It's possible there's a typo in the question's values or the options. However, based on the provided information, the calculated maximum speed is 36ms−1. If I had to choose the closest option, it would be B. 25ms−1 or A. 20ms−1, but 36ms−1 is the direct calculation. I will state the calculated answer.
The maximum speed of the car is 36ms−1.
Q48.
Step 1: Identify the given probabilities and number of trials.
Probability of landing head-up, P(H)=41.
Number of tosses, n=3.
Step 2: Calculate the probability of landing tail-up.
P(T)=1−P(H)=1−41=43
Step 3: Use the binomial probability formula to find the probability of getting exactly one tail in 3 tosses.
The probability of exactly k successes in n trials is given by P(X=k)=(kn)pk(1−p)n−k.
Here, "success" is getting a tail, so p=P(T)=43. We want k=1 tail in n=3 tosses.
P(exactlyonetail)=(13)(43)1(1−43)3−1
P(exactlyonetail)=3×(43)×(41)2
P(exactlyonetail)=3×43×161
P(exactlyonetail)=649
The correct option is A.
The probability of getting exactly one tail is A.649.
Q49.
Step 1: Identify the masses and positions of the particles.
Particle 1: m1=2 kg, (x1,y1)=(3,1)
Particle 2: m2=3 kg, (x2,y2)=(8,6)
Step 2: Calculate the x-coordinate of the center of mass (XCM).
XCM=m1+m2m1x1+m2x2
XCM=2kg+3kg(2kg)(3)+(3kg)(8)
XCM=56+24
XCM=530
XCM=6
Step 3: Calculate the y-coordinate of the center of mass (YCM).
YCM=m1+m2m1y1+m2y2
YCM=2kg+3kg(2kg)(1)+(3kg)(6)
YCM=52+18
YCM=520
YCM=4
The position of their center of mass is (6,4).
The correct option is A.
The position of their center of mass is A.(6,4).
Q50.
Step 1: Identify the given values.
Force, F=14 N
Mass, m=70 kg
Initial speed, u=3ms−1
Final speed, v=7ms−1
Step 2: Apply the Work-Energy Theorem.
The work done by the force is equal to the change in kinetic energy.
W=ΔKE
Fs=21mv2−21mu2
Step 3: Substitute the values and solve for the distance s.
(14N)s=21(70kg)(7ms−1)2−21(70kg)(3ms−1)2
14s=21(70)(49)−21(70)(9)
14s=35(49)−35(9)
14s=1715−315
14s=1400
s=141400
s=100m
The correct option is D.
The distance travelled is D.100m.
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