# A marble dropped from a bridge strikes the water in 5.0 s. what is the height of the bridge? (Answer in meters)A

##### 1 Answer

Jun 6, 2018

#### Explanation:

Use equation of motion

#"S" = "ut" + 1/2"at"^2#

Where

#"S ="# Displacement covered#"u ="# Initial velocity#"a ="# Acceleration (It’s#"9.8 m/s"^2# due to Earths gravity)#"t ="# Time taken to cover displacement#"S"#

Marble is **dropped.** It means initial velocity (

Therefore the equation becomes

#"S" = 1/2"at"^2#

#color(white)("S") = 1/2 × "9.8 m/s"^2 × "(5 s)"^2#

#color(white)("S") = 122.5\ "m"#

Displacement covered by the marble when thrown from the bridge is obviously height of the bridge.