This question is giving me trouble... In an action-adventure film, the hero is s

Question

This question is giving me trouble...

In an action-adventure film, the hero is supposed to throw a grenade from his car, which is going 87.0km/h , to his enemy's car, which is going 127km/h . The enemy's car is 15.9m in front of the hero's when he lets go of the grenade.

If the hero throws the grenade so its initial velocity relative to him is at an angle of 45 ? above the horizontal, what should the magnitude of the initial velocity be? The cars are both traveling in the same direction on a level road. You can ignore air resistance.

Explanation / Answer

relative velocity of enemy car w.r.t. hero is = 127 - 87 = 40 km/hr

or 11.11 m/sec

now let the grenade hits this car with velocity v, in time t.

so we know both the grenade and car will travel same distance "s" in this time t.

so distance travelled by car in time t = 11.11*t

for grenade: v*cos(theta) *t will be distance in horizontal

so,

11.11t = vcos(theta) *t

v = 15.714 m/sec

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.