Answer:
(a) m = 1.6 x 10²¹ kg
(b) K.E = 2.536 x 10¹¹ J
(c) v = 7.12 x 10⁵ m/s
Explanation:
(a)
First we find the volume of the continent:
V = L*W*H
where,
V = Volume of Slab = ?
L = Length of Slab = 4450 km = 4.45 x 10⁶ m
W = Width of Slab = 4450 km = 4.45 x 10⁶ m
H = Height of Slab = 31 km = 3.1 x 10⁴ m
Therefore,
V = (4.45 x 10⁶ m)(4.45 x 10⁶ m)(3.1 x 10⁴ m)
V = 6.138 x 10¹⁷ m³
Now, we find the mass:
m = density*V
m = (2620 kg/m³)(6.138 x 10¹⁷ m³)
<u>m = 1.6 x 10²¹ kg</u>
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(b)
The kinetic energy will be:
K.E = (1/2)mv²
where,
v = speed = (1 cm/year)(0.01 m/1 cm)(1 year/365 days)(1 day/24 h)(1 h/3600 s)
v = 3.17 x 10⁻¹⁰ m/s
Therefore,
K.E = (1/2)(1.6 x 10²¹ kg)(3.17 x 10⁻¹⁰ m/s)²
<u>K.E = 2.536 x 10¹¹ J</u>
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(c)
For the same kinetic energy but mass = 77 kg:
K.E = (1/2)mv²
2.536 x 10¹¹ J = (1/2)(77 kg)v²
v = √(2)(2.536 x 10¹¹ J)
<u>v = 7.12 x 10⁵ m/s</u>
Answer:
15 cm
Explanation:
= Diameter of the coin = 15 mm
= Diameter of the image of coin = 5 mm
= distance of the coin from mirror = 15 cm
= distance of the image of coin from mirror = ?
Using the equation
= - 5 cm
= radius of curvature
Using the mirror equation
= - 15 cm
Part A:
For this part we’re assuming all the kinetic energy of the moving bumper car is converted into elastic potential energy in the spring since the car is brought to rest. Therefore you can find the total kinetic energy to get your answer:
KE = ½ mv^2
KE = ½ (200)(8)^2
KE = 6400 J
Part B:
Now you can use Hooke’s law to find the force:
F = kx
F = (5000)(0.2)
F = 1000 N
Answer:
5) Displacement = +3.125 m
Displacement is in the same direction as the force vector.
6) Force = -53.89 N
Force is in an opposite direction relative to the displacement.
Explanation:
5) We are given;
Force; F = 160 N.
Workdone; W = +500 J
Now, formula for workdone is;
W = Force × displacement
Thus, displacement = Work/force
Displacement = 500/160
Displacement = +3.125 m
Thus, displacement is in the same direction as the force vector.
6) We are given;
Displacement; d = 18 m.
Workdone; W = -970 J
Like in the first answer above,
Workdone = Force × Displacement
Thus;
Force = Workdone/Displacement
Force = -970/18
Force = -53.89 N
Since force is negative and displacement is positive, it means force is in an opposite direction relative to the displacement.
