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Zina [86]
3 years ago
6

Imagine a rock is dropped from the top of a tall building.After 2 seconds of falling the rock is instantaneous speed In approxim

ately 20m/s
Physics
1 answer:
Fantom [35]3 years ago
8 0

This is True.

Explanation:

initial velocity= Vi=0

final velocity= V

acceleration due to gravity= 9.8 m/s²

using the kinematic equation V= Vi+gt

V=0+(9.8)(2)

V= 19.6 m/s which is approximately equal to 20 m/s

Thus after 2 seconds, the instantaneous speed of the rock is approximately 20 m/s.

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In an electric vehicle, each wheel is powered by its own motor. The vehicle weight is 4,000 lbs. By regenerative braking, its sp
Slav-nsk [51]

Answer:

the theoretical maximum energy in kWh that can be recovered during this interval is 0.136 kWh

Explanation:

Given that;

weight of vehicle = 4000 lbs

we know that 1 kg = 2.20462

so

m = 4000 / 2.20462 =  1814.37 kg

Initial velocity V_{i} = 60 mph = 26.8224 m/s

Final velocity V_{f} = 30 mph = 13.4112 m/s

now we determine change in kinetic energy

Δk = \frac{1}{2}m(  V_{i}² - V_{f}² )

we substitute

Δk = \frac{1}{2}×1814.37( (26.8224)² - (13.4112)² )

Δk = \frac{1}{2} × 1814.37 × 539.5808

Δk = 489500 Joules

we know that; 1 kilowatt hour = 3.6 × 10⁶ Joule

so

Δk = 489500 / 3.6 × 10⁶

Δk = 0.13597 ≈ 0.136 kWh

Therefore, the theoretical maximum energy in kWh that can be recovered during this interval is 0.136 kWh

4 0
3 years ago
A projectile is launched with an initial speed of 60.0 m/s at an angle of 30.0° above the horizontal. The projectile lands on a
vodka [1.7K]

Answer:

51.96 m/s^-1

Explanation:

a) see the attachment

b) As we know the velocity of the projectile has two component, horizontal velocity v_ox. and vertical velocity v_oy as shown in the figure. At the highest point of the trajectory, the projectile has only horizontal velocity and vertical velocity is zero. Therefore at the highest point of the trajectory, the velocity of the projectile will be  

v_ox=v_o*cosФ

       =60*cos (30)

      = 51.96 m/s^-1

3 0
3 years ago
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Answer:

pressure, stress pascal N/m2

energy, work, quantity of heat joule N·m

power, radiant flux watt J/s

electric charge, quantity of electricity coulomb -

8 0
3 years ago
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Answers are ONLY allowed to be ionic, polar covalent, and nonpolar covalent.
Luba_88 [7]
A) It will be 2 covalent bonds
B) covalent bonds occur when there’s 2 atoms that share electrons. In this case by sharing the 2 pairs of valence electrons each atom has a total of 8 valence electrons
8 0
2 years ago
chanice drives her scooter 7 km north she stops for lunch and then drives 5 km east what distance did she cover. what was her di
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