consider the motion of projectile A in vertical direction :
v₀ = initial velocity of projectile A in vertical direction = 0 m/s (since the projectile was launched horizontally)
a = acceleration of the projectile = g = acceleration due to gravity = 9.8 m/s²
t = time of travel for projectile A = 3.0 seconds
Y = vertical displacement of projectile A = height of the cliff = h = ?
using the kinematics equation along the vertical direction as
Y = v₀ t + (0.5) a t²
h = (0) (3.0) + (0.5) (9.8) (3.0)²
h = 44.1 m
Answer:
6.0 s
98 m/s
Explanation:
The radius of the planet is much bigger than the height of the tower, so we will assume the acceleration is constant. Neglect air resistance.
Acceleration due to gravity on this planet is:
a = GM / r²
a = (6.67×10⁻¹¹ m³/kg/s²) (2.7 × 1.48×10²³ kg) / (1.7 × 750,000 m)²
a = 16.4 m/s²
The height of the tower is:
Δy = 96 × 3.05 m
Δy = 293 m
Given v₀ = 0 m/s, find t and v.
Δy = v₀ t + ½ at²
(293 m) = (0 m/s) t + ½ (16.4 m/s²) t²
t = 6.0 s
v² = v₀² + 2aΔy
v² = (0 m/s)² + 2 (16.4 m/s²) (293 m)
v = 98 m/s
The last choice on the list is the correct one, for both #2 and #3.
In order for two vectors to add to zero, they must have the same magnitude and point in opposite directions.
Two perpendicular vectors, by definition, make a right angle with each other whereas two vectors pointing in opposite directions form a straight line.
Because of this, two perpendicular vectors with nonzero magnitudes will never add to zero.
