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3 years ago

14

Holden is trying to turn man the velocity of his car, he went 20 meters east, turned around and left 40 meters less, he turned t

he car one more time, and when 35 meters east, his car was 15 metres from the starting line. This took 5 seconds, what is the car
velocity

1 answer:

Grace [21]3 years ago

4 0

Answer:

3 m/s east

Explanation:

The velocity of the car is given by:

$v=\frac{d}{t}$

where

d is the displacement

t is the time taken

The displacement of the car does not depend on the path of the car, but just on it the difference between its final position and its starting position, so it is equal to 15 metres east. The time taken is 5 seconds, therefore the velocity is equal to

$v=\frac{15 m}{5 s}=3 m/s$

and the direction is east.

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If the period of a satellite is T=24 h = 86400 s that means it is in geostationary orbit around Earth. That means that the force of gravity Fg and the centripetal force Fcp are equal:

Fg=Fcp

m*g=m*(v²/R),

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Masses cancel out and we have:

G*(M/r²)=v²/R, R=r so:

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r=G*(M/v²), since v=ωr it means v²=ω²r² and we plug it in,

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3 years ago

3. A simple way to state Newton’s first law is:

MrRissso [65]

Explanation:

A simple way to state Newton's first law is:

For every action force, there is a reaction force which is equal in magnitude and opposite in direction.

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3 years ago

determine the greates possile acceleration of the 975 kg race car so that its front wheels do not leace the gorund

wolverine [178]

<u>Answer</u>:

The greatest possible acceleration of the car is $a_G= 6.78 m/s^2$

<u>Explanation</u>:

$N_A+N_B-Mg = 0$

$-N_Aa +N_B(b-a)- \mu_s N_Bh - \mu_s N_Ah = 0$

$0.8N_B +0.8N_A = 975a_G$

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$-N_A(1.82) + N_B(2.20 -1.82) -0.9N_B(0.55)-0.8N_A(0.55)=0$

$-N_A(1.82) +0.38 N_B -0.44N_B -0.44N_A=0$

$-2.26N_A -0.06N_B= 0$ ----------------(2)

Solving the equation (1) and(2)

$N_A + N_B = 9564.75$

$-2.26N_A-0.06N_B=0$

$N_A = -260.85N$

$N_B = 9825.60N$

$\mu_s N_B + \mu_s N_A = 975a_G$

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Next lets assume that the front wheels contact with the ground N_A = 0

$F_B = Ma_G$

$N_B = M_g$

$N_B - M_g = 0$

$N_B(b-a) –F_Bh = 0$

$F_B = 975a_G$

$N_B-975(9.8) = 0$

$N_B=9564.75N$

$9564.75(2.20 -1.82) -F_B(0.55)=0$

$\frac{3634.605}{0.55}=F_B$

$F_B = 6608.3$

$F_B = Ma_G$

$6608.3 = 975a_G$

$a_G = 6.7778 m/s^2$

$a_G_2 = 6.78m/s^2$

Choosing the critical case

$a_G = min(a_G_1 ,a_G_2)$

$a_G = min(7.848, 6.78)$

$a_G= 6.78 m/s^2$

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3 years ago

An elevator is moving downward when someone presses the emergency stop button. The elevator comes to rest a short time later. Gi

Oksanka [162]

Answer:

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Explanation:

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tiny-mole [99]

Answer:

(A) 18 km/h

Explanation:

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3 years ago